Diabetic autonomic neuropathy: Abnormal cardiovascular reactions under general anesthesia

Summary The influence of diabetic autonomic neuropathy upon the behavior of the circulatory system was investigated in 56 patients who had undergone ophthalmological surgery. A standardized test combination (variability in heart rate during deep breathing, Valsalva ratio, 3015 ratio, change in blood pressure from lying to standing, sustained handgrip test) was used to study the patients' cardiovascular reflectory reactions. The patients were then divided into the following groups: Group I, non-diabetics Group II, diabetics without autonomic neuropathy Group III, diabetics with autonomic neuropathy The anesthetic (induction by barbiturates and conduction by inhalation agents) and the surgical procedure (pars plana vitrectomy) were standardized and always identical. During anesthesia patients in group III experienced hypotensive reactions (systolic blood pressure below 90 mm Hg) significantly more often (72.2%) than patients in group I (25%). In order to achieve stability in blood pressure the patients of group III had to be given vasoactive drugs much more often (77.8%) than the patients of group I (12.5%) and those of group II (35.7%). We found a significant correlation between the degree of autonomic dysfunction and the largest drop in blood pressure under narcosis (r=–0.60,P<0.001). However, marked variability in heart rate and cardiac rhythm disorders during anesthesia were seen only in patients of groups I and II. These results prove the atypical hemodynamic behavior and especially the extreme instability in blood pressure in diabetic autonomic neuropathy under general anesthesia. Therefore we consider it to be very helpful to check the cardiovascular reflectory status of diabetics preoperatively.Abbreviations AN autonomic neuropathy - AV atrioventricular - BP blood pressure - bpm beats per minute - cm centimeter - f female - HR heart rate - m male - PD diastolic blood pressure - PS systolic blood pressure     

Quantitative measurements of vibration threshold in healthy adults and acrylamide workers

Summary The early detection of impaired of vibration sensation is necessary in order to monitor the adverse effects in workers occupationally exposed to neurotoxic chemicals such as acrylamide. The conventional neurological examination which assesses vibration sensation by utilizing a tuning fork is relatively insensitive for this purpose. In the present study, the Vibratron II, a new device for the quantitative measurement of vibration thresholds, was used in 105 healthy Chinese adults. A new testing procedure combining the two-alternative forced-choice procedure and the yes-or-no method-of limits procedure showed good reliability and was less time consuming. The results indicate that significant differences in the vibration threshold of index fingers and great toes were found neither between males and females, nor between the left and the right side. However, there was an age-dependent increase in vibration threshold in nonexposed healthy subjects. The vibration thresholds of 41 workers exposed to acrylamide detected by the Vibratron II were significantly higher than those of the healthy adults in the same age group. The quantitative measurement of vibration threshold seems to be potentially useful for screening peripheral nerve dysfunction in field studies.     

电生理学检查对慢性酒精中毒性周围神经病的早期诊断价值

目的：通过对慢性酒精中毒患者做电生理学检查,以及早发现无自觉症状期的周围神经损害;方法：对６４例慢性酒精中毒患者行常规肌电图检查与神经传导速度测定;结果：发现在慢性酒精中毒性周围神经病无临床自觉症状时,肌电图与神经传导速度均可出现异常改变;结论：提示肌电图与神经传导速度可作为早期诊断慢性酒精中毒性周围神经病的有效诊断方法。     

Autosomal recessive hypermyelinating neuropathy

We studied three patients from two kinships, affected by early onset hereditary motor and sensory neuropathy with probable autosomal recessive inheritance (HMSN type III). Morphological studies of sural nerve biopsies revealed an abnormal myelin proliferation. Two adult patients with long-term follow up, lost ability to walk at 28 and 22 years and showed severe involvement of the cranial nerves. Our observations suggest that hypermyelination neuropathy with early onset is a progressive disease with poor long-term prognosis. In one kinship the occurrence of the disease in two sibs of both sexes but not in parents, is consistent with an autosomal recessive inheritance. Familial cases of hypermyelination neuropathy have not been described in previous reports. Morphological aspects of this condition are compared with other forms of hypermyelination neuropathy.Supported by Telethon-Italy for the project: Chronic inflammatory polyradiculoneuropathy: electrophysiological and immunopathological studies     

A comparative trial of anti-glycoconjugate antibody assays: IgM antibodies to GM1

IgM class antibodies against the ganglioside GM1 have been found in a subgroup of patients with lower motor neuron syndromes and multifocal motor neuropathies (MMN). The pathogenic relevance of these antibodies is still unclear, but some MMN patients with IgM antibodies against GM1 seem to profit from immunosuppressive therapy. A reliable test for IgM antibodies against GMl may be useful for identifying these patients. We have assessed the comparability of the ELISA tests used for the determination of IgM against GM1 by sending coded serum samples to nine laboratories. In three samples high-titre IgM antibodies against GM1 were detected by all laboratories. This result was confirmed by dot blot immunodetection and thin-layer chromatography immuno-overlay. Seven samples were read as negative by nearly all laboratories. Major discrepancies between laboratories were noted in the analysis of one sample with results ranging from negative to high titre. Participating laboratories: N. Baumann and A. Ben Younes-Chennoufi, Neurobiologie cellulaire moleculaire et clinique, INSERM U134, Hôpital de la Sâpetrière, Paris, France; P. Fredman and L. Svennerholm, Department of Psychiatry and Neurochemistry, Goteborg University, Sweden; N. Gregson and R. A. C. Hughes, Department of Neurology, Guy's and St. Thomas's Medical and Dental School, London, UK; A. A. Ilyas, Department of Neurosciences, University of Medicine & Dentistry of New Jersey, New Jersey Medical School, Newark, N. J., USA; A. Pestronk, Division of Neuromuscular Diseases, Washington University School of Medicine, St. Louis, Mo., USA; A. J. Steck, Service de Neurologie, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland (current address: Department of Neurology, University of Basle); H. Willison, Department of Neurology, University of Glasgow, Glasgow, UK     

The distribution of systemically administered [3H]-paclitaxel in rats: a quantitative autoradiographic study

Paclitaxel is an important agent in the treatment of many common malignancies. Although the symptomatic peripheral neuropathy caused by this drug is its principal nonhematologic toxicity, little is known about the distribution of paclitaxel within the peripheral or central nervous system following systemic administration. In order to study paclitaxel's distribution in neural and extraneural tissues, adult Sprague-Dawley rats were sacrificed 2 h after a tail vein injection of [³H]-paclitaxel (0.03 mg/kg, 250 Ci/rat). Samples of lung, heart, liver, spleen, kidney, skeletal muscle, brain, spinal cord, dorsal root ganglion, and peripheral nerve were then removed and snap-frozen. These tissues were sectioned at 10 m in a cryostat and exposed to autoradiography film for 2 weeks. The distribution and concentrations of [³H]-paclitaxel in plasma, urine and cerebrospinal fluid were also determined using liquid scintillation spectrometry. [³H]-Paclitaxel concentrations (and organ/plasma concentration ratios) in plasma, urine and cerebrospinal fluid were 2.6 nM (1), 38 nM (15) and 0.7 nM (0.3), respectively. A relatively homogeneous distribution of [³H]-paclitaxel was observed in liver [412 nM (151)], spleen [351 nM (133)], heart [319 nM (117)], lung [268 nM (93)] and muscle [69 nM (26)]. Higher concentrations of [³H]-paclitaxel were noted in the portal triads [869 nM (361)], glomeruli [797 nM (304)], and renal medulla [961 nM (363)], which may reflect biliary excretion and glomerular filtration. A high concentration of [³H]-paclitaxel was also noted in the choroid plexus [432 nM (167)], but [³H]-paclitaxel was not detected in the brain parenchyma, spinal cord, dorsal root ganglion, peripheral nerve, or the testicles. The pathogenesis of paclitaxelinduced neurotoxicity remains obscure given its limited distribution in the nervous system. In addition, these results suggest that systemically administered paclitaxel is not likely to be effective for the treatment of malignancies in the testes or the nervous system.     

Surgical Findings in Idiopathic Trigeminal Neuropathy Mimicking a Trigeminal Neurinoma

Summary  Idiopathic trigeminal neuropathy is a benign disorder where the main clinical feature is facial numbness limited to the territory of one or more divisions of the trigeminal nerve, persisting for a few weeks to several years and in which no underlying disease can be identified. The case of a 37-year-old man with a brief history of sensory and motor trigeminal symptoms who showed magnetic resonance imaging (MRI) findings consistent with a small trigeminal neurinoma is reported. The patient was operated on but no tumour could be found during surgery and a biopsy was taken from the portio major. Pathological diagnosis was chronic non granulomatous inflammatory reaction with areas of coagulation necrosis. Control MRI showed complete resolution of the trigeminal abnormalities. It is concluded that in patients with MRI findings suggestive of a small trigeminal schwannoma, benign idiopathic trigeminal neuropathy should also be considered in the differential diagnosis. A conservative approach with sequential MRI studies may avoid an unnecessary surgical exploration.     

Development of weakness in patients with chronic inflammatory demyelinating polyneuropathy and only sensory symptoms at presentation: A long-term follow-up study

This long-term follow-up study examined patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and only sensory symptoms at first presentation, with emphasis on the development of motor symptoms and long-term disability. From all CIDP patients referred to our Department between 1987 and 1995, seven had only sensory symptoms at first clinical presentation. These were investigated according to a standard protocol, including a quantified clinical neurological examination and nerve conduction studies. The mean duration of the disease before weakness developed was 3.1 years, but varied considerably (0.8–6.3 years). At follow-up, weakness developed in five patients and persisted in three of them. Five patients were not seriously incapacitated by their disease (Rankin 1 or 2), four of them being in remission now and one showing a very slow progression of disease. Two patients were moderately disabled (Rankin 3); one had severe persistent sensory ataxia and only weakness during relapses and one had stepwise progression and moderate weakness. Motor nerve conduction studies revealed that the most notable worsening in the entire group of patients was a decrease in distal compound muscle action potential amplitudes, indicating the development of distal conduction block or axonal degeneration. These findings show that CIDP with only sensory symptoms is a transient clinical stage that precedes the appearance of weakness in about 70% of patients. The long-term prognosis does not differ from that of patients with CIDP who have weakness at the beginning of the disease. Received: 3 December 1998 Received in revised form: 17 May 1999 Accepted: 2 July 1999     

遗传性压迫易感性神经病(4例临床与病理)

目的从临床、电生理及病理方面对遗传性压迫易感性神经病（ＨＮＰＰ）进行探讨,以提高对本病的认识。方法４例经临床及腓肠神经活检确诊,肌电图检测临床受累或未受累的肢体的感觉或运动传导速度;腓肠神经活检标本分别做ＨＥ、Ｍａｓｏｎ染色和Ｆｌｅｍｍｉｎｇ染色光镜观察。结果肌电图为广泛神经传导异常,甚至出现在临床未受累的神经支配区;腓神经活检显示部分神经纤维明显增粗,轴索正常。结论ＨＮＰＰ与遗传关系密切,但也有散发,电生理检查是重要的筛选手段,神经活检见到髓鞘增粗或典型的腊肠样结构是重要的确诊手段